Internal combustion engines comprise intake and exhaust valves, each valve including a head and a valve stem integrally secured to the head, and reciprocally mounted in a valve stem guide. As the valve stem typically operates in a substantial volume of lubricating oil, it is preferable to limit the amount of oil consumed by the engine. To control oil consumption, valve stem seal assemblies are mounted on the valve guides to meter oil flow between the stems and guides.
Valve stem seal assemblies are known which include a metallic casing or shell adapted to retain a resilient seal body, the seal body typically made of an elastomer base material. A garter spring or retaining ring is supported in an exterior external groove of the seal body, and used to provide a radially compressive force between the seal body and the stem. Such garter springs or retaining rings may be time-consuming or difficult to install, and are subject to unwanted separation from the rest of the assembly. Nor are they protected from adverse operational conditions of internal combustion engines. The adverse conditions include elevated engine temperature, corrosion, loss of spring load, and the possibility of the component becoming nonfunctional. Therefore, unwanted assembly failure may result.